On June 17, 1775, American colonists, defending a forward redoubt on Breed’s Hill, ran out of gunpowder, and their position was overrun by British troops. The Battle of Bunker Hill resulted in the death of 140 colonists and 226 British soldiers, setting the stage for major combat throughout the colonies. American colonists lacked many necessary weapons. They had almost no gunpowder, few field cannons, and no warships. Yet, they fought on with the weapons at hand for 6 long years.
In the spring of 2020, American society has been shaken by the COVID-19 pandemic. Hospitals have been overrun with thousands of people infected with the disease. Some hospitals are breaking under the crush of intensely ill people filling up and spilling out of intensive care units. We are in a war, fighting a viral disease with a limited supply of weapons. We do not have access to the most powerful medical munitions: easily available rapid testing, proven antiviral medications, and an effective vaccine. Nevertheless, clinicians and patients are courageous, and we will continue the fight with the limited weapons we have until the pandemic is brought to an end.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The virus is aptly named because it is usually transmitted through close contact with respiratory droplets. The disease can progress acutely, and some people experience a remarkably severe respiratory syndrome, including tachypnea, hypoxia, and interstitial and alveolar opacities on chest x-ray, necessitating ventilatory support. The virus is an encapsulated single-stranded RNA virus. When viewed by electron microscopy, the virus appears to have a halo or crown, hence it is named “coronavirus.” Among infected individuals, the virus is present in the upper respiratory system and in feces but not in urine.1 The World Health Organization (WHO) believes that respiratory droplets and contaminated surfaces are the major routes of transmission.2 The highest risk of developing severe COVID-19 disease occurs in people with one or more of the following characteristics: age greater than 70 years, hypertension, diabetes, respiratory disease, heart disease, and immunosuppression.3,4 Pregnant women do not appear to be at increased risk for severe COVID-19 disease.4 The case fatality rate is highest in people 80 years of age or older.5
Who is infected with SARS-CoV-2?
Rapid high-fidelity testing for SARS-CoV-2 nucleic acid sequences would be the best approach to identifying people with COVID-19 disease. At the beginning of the pandemic, testing was strictly rationed because of lack of reagents and test swabs. Clinicians were permitted to test only a minority of people who had symptoms. Asymptomatic individuals were not eligible to be tested. This terribly flawed approach to screening permitted a vast army of SARS-CoV-2–positive asymptomatic and mildly symptomatic people to circulate unchecked in the general population, infecting dozens of other people, some of whom developed moderate or severe disease. The Centers for Disease Control and Prevention (CDC) has reported on 7 independent clusters of COVID-19 disease, each of which appear to have been caused by one asymptomatic infected individual.6 Another cluster of COVID-19 disease from China appears to have been caused by one asymptomatic infected individual.7 Based on limited data, it appears that there may be a 1- to 3-day window where an individual with COVID-19 may be asymptomatic and able to infect others. I suspect that we will soon discover, based on testing for the presence of high-titre anti SARS-CoV-2 antibodies, that many people with no history of illness and people with mild respiratory symptoms had an undiagnosed COVID-19 infection.
As testing capacity expands we likely will be testing all women, including asymptomatic women, before they arrive at the hospital for childbirth or gynecologic surgery, as well as all inpatients and women with respiratory symptoms having an ambulatory encounter.
With expanded testing capability, some pregnant women who were symptomatic and tested positive for SARS-CoV-2 have had sequential long-term follow-up testing. A frequent observation is that over one to two weeks the viral symptoms resolve and the nasopharyngeal test becomes negative for SARS-CoV-2 on multiple sequential tests, only to become positive at a later date. The cause of the positive-negative-negative-positive test results is unknown, but it raises the possibility that once a person tests positive for SARS-CoV-2, they may be able to transmit the infection over many weeks, even after viral symptoms resolve.
Continue to: COVID-19: Respiratory droplet or aerosol transmission?